The ability to receive a real-time status report about what is happening with a trailer being towed by a vehicle fitted with a system that combines electronics, power switching, and connectors is edging closer to mass-production reality.
Yazaki’s IntelliTow provides more than what is “available today from the conventional relay and fusing systems,” said Dan Moore, Yazaki Product Manager. “We are targeting to be production ready as soon as the 2010 model year. We’ve done all of the preliminary evaluation work using prototype parts.”
The smart trailer tow device uses solid-state electronics—including smart field-effect transistors—and protocol-specific bus integrated circuits. “The smart field-effect transistors provide short-circuit trailer wiring protection and diagnostics feedback to the microprocessor,” said Moore.
Since commands and diagnostics are handled via a two-way communications bus, “this reduces wiring complexity, size, and weight associated with towing. The software allows for real-time diagnostics reporting on the CAN (controller area network) or LIN (local interconnect network) bus while on the road. IntelliTow monitors a variety of functions and provides short-circuit protection with auto-retry, which essentially eliminates the possibility of blowing a fuse due to an intermittent trailer fault,” said Moore.
The system’s software also handles load-shedding duties. “When a low vehicle battery is detected, trailer charging is disabled instead of letting the vehicle battery drain,” said Moore. “And if there is excessive electrical loading on the trailer, the battery charge can be disabled to protect the trailer/vehicle connector from becoming too hot.”
Among the unique features of IntelliTow is trailer load learning. The system can detect when one half of the filaments are not functioning, such as the turn/brake circuit. “That means a complete failure is not required in order to detect a change in electrical load,” Moore said. Yazaki’s trailer-tow system also offers an optional boat-launch mode.
“This mode is recommended as a precaution to separate the electrical connection so that the trailer lights are protected from shorts or bulb fracture in case of a thermal shock due to water intrusion,” Moore explained. “The boat-launch mode allows for one person to disable the trailer loads without getting out of the vehicle. Reverse trailer output is always maintained as a means of activating the trailer’s built-in electric reverse solenoid of the surge brake system.”
IntelliTow’s optional dual-current level for four- and seven-pin connections means that a lower current level for the four pin—separate from the seven pin—is possible. “This provides for better protection of the four-pin trailer wiring since the vehicle’s fuse ratings are selected for larger currents on the seven-pin connector,” said Moore.
Yazaki officials expect that automakers will initially integrate IntelliTow into truck and SUV architectures. “Ultimately, we may consider offering this module as an aftermarket and recreational vehicle product. Yazaki has designed IntelliTow as a pass-through circuit so that the module can be easily incorporated with OEM or aftermarket trailer brake controllers,” said Moore.